To investigate the effects of γ rays on DNA polymerase β properties and its DNA repair functions before or after γ rays exposure, DNA polymerase βactivity, gene expression and mRNA levels in SMMC-LTNM hepatomas ho...To investigate the effects of γ rays on DNA polymerase β properties and its DNA repair functions before or after γ rays exposure, DNA polymerase βactivity, gene expression and mRNA levels in SMMC-LTNM hepatomas horn on nude mice or the samples of the liver cancer tissues from 15 patients were measured with 3H-TTP incorporation test, immunocytochemistry and cytoplasmic dot hybridization analysis, respectively.Irradiation was carried out with 60Co-γ rays at ice bath. It was found that DNA polymerase β activity, gene expression and the amount of mRNA were much higher in hepatoma cells than those in normal hepatocytes (P<0.01). In vitro studies, the enzyme activity both in hepatoma and normal liver cells appeared unchanged within 40 Gy γ-ray exposure. Following whole-body exposure of the nude mice bearing SMMC-LTNM with 2 Gy or 4 Gy of γ rays, DNA polymerase β activity in hepatoma increased temorarily at 48 hours postirradiation, and its gene expression seemed more active.The euzyme mRNA increased to 1.76-fold of the control group. 72 hours after exposure, all of these changes returned to normal levels. DNA polymerase βparticipated in DNA repair synthesis and this effect was different between hepatoma and hepatocytes because there were some biologic differences of the enzyme between hepatoma cells and normal liver cells. These data suggested that DNA polymeraseβactivity, its gene expression and mRNA level in hepatomas could increased temporarily after γ rays exposure, which may facilitate the cells to repair DNA damages from radiation.展开更多
The pathophysiology of amyotrophic lateral sclerosis （ALS） is particularly challenging due to the heteroge- neity of its clinical presentation and the diversity of cellular, molecular and genetic peculiarities invol...The pathophysiology of amyotrophic lateral sclerosis （ALS） is particularly challenging due to the heteroge- neity of its clinical presentation and the diversity of cellular, molecular and genetic peculiarities involved. Molecular insights unveiled several novel genetic factors to be inherent in both familial and sporadic dis- ease entities, whose characterizations in terms of phenotype prediction, pathophysiological impact and putative prognostic value are a topic of current researches. However, apart from genetically well-defined high-confidence and other susceptibility loci, the role of DNA damage and repair strategies of the genome as a whole, either elicited as a direct consequence of the underlying genetic mutation or seen as an autono- mous parameter, in the initiation and progression of ALS, and the different cues involved in either process are still incompletely understood. This mini review summarizes current knowledge on DNA alterations and counteracting DNA repair strategies in ALS pathology and discusses the putative role of unconventional DNA entities including transposable elements and extrachromosomal circular DNA in the disease process. Focus is set on SODl-related pathophysiology, with extension to FUS, TDP-43 and C90RF72 mutations. Advancing our knowledge in the field will contribute to an improved understanding of this relentless dis- ease, for which therapeutic options others than symptomatic approaches are almost unavailable.展开更多
This study evaluated the correlation between DNA degradation of the splenic lymphocytes and the early time of death, examined the early time of death by computerized image analysis technique （CIAT） and identified th...This study evaluated the correlation between DNA degradation of the splenic lymphocytes and the early time of death, examined the early time of death by computerized image analysis technique （CIAT） and identified the best parameter that quantitatively reflects the DNA degradation. The spleen tissues from 34 SD rats were collected, subjected to cell smearing every 2 h within the first 36 h after death, stained by Feulgen-Van＇s staining, three indices reflecting DNA content in splenic lymphocytes, including integral optical density （IOD）, average optical density （AOD）, average gray scale （AG） were measured by the image analysis. Our results showed that IOD and AOD decreased and AG increased over time within the first 36 h. A stepwise linear regression analysis showed that only AG was fitted. A correlation between the postmortem interval （PMI） and AG was identified and the corresponding regression equation was obtained. Our study suggests that CIAT is a useful and promising tool for the estimation of early PMI with good objectivity and reproducibility, and AG is a more effective and better quantitative indicator for the estimation of PMI within the first 36 h after death in rats.展开更多
BACKGROUND: Alterations in DNA methylation occur during the pathogenesis of human tumors. In this study, we investigated the influence of DNA methyltransferase 3b (DNMT3b) on fragile histidine trial (FHIT) expression ...BACKGROUND: Alterations in DNA methylation occur during the pathogenesis of human tumors. In this study, we investigated the influence of DNA methyltransferase 3b (DNMT3b) on fragile histidine trial (FHIT) expression and on DNA methylation of the FHIT promoter region in the hepatoma cell line SMMC-7721. METHODS: DNMT3b siRNA was used to down-regulate DNMT3b expression. DNMT3b and FHIT proteins were determined by Western blotting. Methylation-specific PCR was used to analyze the methylation status of the FHIT gene. RESULTS: After DNMT3b siRNA transfection, the expression of DNMT3b was inhibited in SMMC-7721 cells, and the expression of FHIT was significantly higher than that in the control group. There was no significant difference in methylation status between the DNMT3b siRNA transfected cells and control cells. CONCLUSION: DNMT3b may play an important role in regulation of FHIT expression in hepatoma SMMC-7721 cells, but not through methylation of the FHIT promoter. (Hepatobiliary Pancreat Dis Int 2009; 8: 273-277)展开更多
In order to investigate the intratumoral DNA ploid heterogeneity (PH) in esophageal squamous cell carcinoma and its clinical-pathological significance, nuclear DNA ploidy of 80 cases of squamous cell carcinoma of the ...In order to investigate the intratumoral DNA ploid heterogeneity (PH) in esophageal squamous cell carcinoma and its clinical-pathological significance, nuclear DNA ploidy of 80 cases of squamous cell carcinoma of the esophagus were determined with multiple samples removed from the same tumor, using a flow cytometry (FCM) technique. 240 samples for flow cytimetric DNA analysis were taken from 3 different parts if each tumor of 80 cases of specimens. DNA measurement was were present in a tumor or the variation in DI value among 3 peaks in each tumor was greater than 10%. Further more at last, comparison or clinical-pathological characteristics was performed between PHTs and N-PHT which has a similar ploid pattern in 3 sampling spots of each tumor (non PHT). DNA indices ranged from 0.77～1.74, and the incidence of DNA AN was 88. 8% (71/80) in this series. Of 80 cases, 38 cases (47. 5%, 38/80) showed intratumoral heterogeneity in DNA ploidy. The heterogeneity in DNA ploidy was related to the extent of wall penetration by the tumor,the incidence of lymph node metastasis and the patients's prognosis, not to histological grades and size of the tumor. There is PH phenomena in esophageal squmous cell carcinoma, and DNA PH may be a more exact indicator in reflecting the biological chatacteristics of the tumor and patient's prognosis.展开更多
AIM To evaluate the relationship between the expression of Ki 67 antigen and the pathobiological behaviours of gastric cancers especially their distant metastases. METHODS Fifty six specimens of gastric cancer ro...AIM To evaluate the relationship between the expression of Ki 67 antigen and the pathobiological behaviours of gastric cancers especially their distant metastases. METHODS Fifty six specimens of gastric cancer routinely fixed in formalin and embedded in paraffin (FFEP) were studied by immunohistochemical method. RESULTS Expression of Ki 67 antigen was significantly related to the distant metastases to liver, ovary and adrenal gland ( P <0 005), but not related to the histological type, growth pattern, depth of invasion, histological differentiation and the metastases to local lymph nodes ( P >0 05). Furthermore, the Ki 67 antigen expression was significantly related to the DNA aneuploidy pattern, which is closely related to poor prognosis ( P <0 05). CONCLUSION Overexpression of Ki 67 can be used as an objective marker of the proliferative activity for predicting prognosis of gastric cancer and metastatic potential to distant organs.展开更多
Summary： To determining the postmortem interval （PMI） through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique （IAT）. The brain and spleen t...Summary： To determining the postmortem interval （PMI） through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique （IAT）. The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van＇s staining, Three indices reflecting DNA in brain cells （astrocytes） and splenic lymphocytes, including integral optical density （IOD）, average optical density （AOD）, average gray （AG） were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5 36 h. A correlation between the PMI and gray parameters （IOD,AOD and AG） was identified and the corresponding regression equation was obtained. The parameters （IOD, AOD and AG） were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.展开更多
AIM The food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces colon and mammary gland tumors in rats and has been implicated in the etiology of human colorectal cancer. This study was co...AIM The food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces colon and mammary gland tumors in rats and has been implicated in the etiology of human colorectal cancer. This study was conducted to examine the potentially preventive effect of Chinese cabbage (Brassica chinensis), a brassica vegetable most commonly consumed in China, against this carcinogen-induced DNA adduct formation in rats and its possible mechanisms.METHODS Sprague-Dawley rats were maintained for 10 days on basal diet or diet containing 20% (w/ w) freeze-dried cabbage powder prior to administration of a single dose of PhIP (10 mg/ kg) by oral gavage. Rats were sacrificed at 20 h after PhIP treatment and PhIP-DNA adducts in the colon, heart, lung and liver were analyzed using 32P-postlabeling technique. Levels of hepatic cytochrome P450 (CYP) 1A1 and 1A2, as indicated by 7-ethoxyresorufin O-deethylase and 7-methlxyresorufin O-demethylase activity, and cytosolic glutathione S-transferases (GSTs) towards 1-chloro-2, 4-dinitrobenzene (CDNB) in the liver, lung and colon were measured.RESULTS Rats pre-treated with Chinese cabbage and given a single dose of PhIP had reduced levels of PhIP-DNA adducts in the colon, heart, lung and liver, with inhibition rates of 82.3%, 60.6%, 48.4% and 48.9%, respectively (P＜0.01). The enzyme assays revealed that Chinese cabbage induced both CYP1A1 and 1A2 activity, but the induction was preferential for CYP1A1 over 1A2 (81% vs 51%). GST activity towards CDNB in the liver and lung, but not colon, was also significantly increased by cabbage treatment.CONCLUSION The results indicate that Chinese cabbage has a preventive effect on PhIP-initiated carcinogenesis in rats and the mechanism is likely to involve the induction of detoxification enzymes.展开更多
Hypermethylation of the gene regulatory regions are common for many cancer diseases. In this work we applied GLAD-PCR assay for identificating of the aberrantly methylated RCGY sites in the regulatory regions of some ...Hypermethylation of the gene regulatory regions are common for many cancer diseases. In this work we applied GLAD-PCR assay for identificating of the aberrantly methylated RCGY sites in the regulatory regions of some downregulated genes in tissue samples of lung cancer(LC). This list includes EFEMP1, EPHA5, HOXA5, HOXA9, LHX1, MYF6, NID2, OTX1, PAX9, RARB, RASSF1 A, RXRG, SIX6, SKOR1 and TERT genes. The results of DNA samples from 40 cancer and 25 normal lung tissues showed a good diagnostic potential of selected RCGY sites in regulatory regions of MYF6, SIX6, RXRG, LHX1, RASSF1 A and TERT genes with relatively high sensitivity(80.0 %) and specificity(88.0 %) of LC detection in tumor DNA.展开更多
文摘To investigate the effects of γ rays on DNA polymerase β properties and its DNA repair functions before or after γ rays exposure, DNA polymerase βactivity, gene expression and mRNA levels in SMMC-LTNM hepatomas horn on nude mice or the samples of the liver cancer tissues from 15 patients were measured with 3H-TTP incorporation test, immunocytochemistry and cytoplasmic dot hybridization analysis, respectively.Irradiation was carried out with 60Co-γ rays at ice bath. It was found that DNA polymerase β activity, gene expression and the amount of mRNA were much higher in hepatoma cells than those in normal hepatocytes (P<0.01). In vitro studies, the enzyme activity both in hepatoma and normal liver cells appeared unchanged within 40 Gy γ-ray exposure. Following whole-body exposure of the nude mice bearing SMMC-LTNM with 2 Gy or 4 Gy of γ rays, DNA polymerase β activity in hepatoma increased temorarily at 48 hours postirradiation, and its gene expression seemed more active.The euzyme mRNA increased to 1.76-fold of the control group. 72 hours after exposure, all of these changes returned to normal levels. DNA polymerase βparticipated in DNA repair synthesis and this effect was different between hepatoma and hepatocytes because there were some biologic differences of the enzyme between hepatoma cells and normal liver cells. These data suggested that DNA polymeraseβactivity, its gene expression and mRNA level in hepatomas could increased temporarily after γ rays exposure, which may facilitate the cells to repair DNA damages from radiation.
基金supported by the Ministry for Economics,Sciences and Digital Society of Thuringia(TMWWDG),in the framework of the Pro Excellence Initiative Regener Aging(Regener Aging-FSU-I-03/14 to AK)the Interdisciplinary Center for Clinical Research(IZKF)Jena(Project FF01 to AK)
文摘The pathophysiology of amyotrophic lateral sclerosis （ALS） is particularly challenging due to the heteroge- neity of its clinical presentation and the diversity of cellular, molecular and genetic peculiarities involved. Molecular insights unveiled several novel genetic factors to be inherent in both familial and sporadic dis- ease entities, whose characterizations in terms of phenotype prediction, pathophysiological impact and putative prognostic value are a topic of current researches. However, apart from genetically well-defined high-confidence and other susceptibility loci, the role of DNA damage and repair strategies of the genome as a whole, either elicited as a direct consequence of the underlying genetic mutation or seen as an autono- mous parameter, in the initiation and progression of ALS, and the different cues involved in either process are still incompletely understood. This mini review summarizes current knowledge on DNA alterations and counteracting DNA repair strategies in ALS pathology and discusses the putative role of unconventional DNA entities including transposable elements and extrachromosomal circular DNA in the disease process. Focus is set on SODl-related pathophysiology, with extension to FUS, TDP-43 and C90RF72 mutations. Advancing our knowledge in the field will contribute to an improved understanding of this relentless dis- ease, for which therapeutic options others than symptomatic approaches are almost unavailable.
基金The project was supported by a grant form the Wuhan Mu-nicipal Chengguang Research Program (No 20015005049)
文摘This study evaluated the correlation between DNA degradation of the splenic lymphocytes and the early time of death, examined the early time of death by computerized image analysis technique （CIAT） and identified the best parameter that quantitatively reflects the DNA degradation. The spleen tissues from 34 SD rats were collected, subjected to cell smearing every 2 h within the first 36 h after death, stained by Feulgen-Van＇s staining, three indices reflecting DNA content in splenic lymphocytes, including integral optical density （IOD）, average optical density （AOD）, average gray scale （AG） were measured by the image analysis. Our results showed that IOD and AOD decreased and AG increased over time within the first 36 h. A stepwise linear regression analysis showed that only AG was fitted. A correlation between the postmortem interval （PMI） and AG was identified and the corresponding regression equation was obtained. Our study suggests that CIAT is a useful and promising tool for the estimation of early PMI with good objectivity and reproducibility, and AG is a more effective and better quantitative indicator for the estimation of PMI within the first 36 h after death in rats.
基金supported by a grant from the National Natural Science Foundation of China(No.30571814)
文摘BACKGROUND: Alterations in DNA methylation occur during the pathogenesis of human tumors. In this study, we investigated the influence of DNA methyltransferase 3b (DNMT3b) on fragile histidine trial (FHIT) expression and on DNA methylation of the FHIT promoter region in the hepatoma cell line SMMC-7721. METHODS: DNMT3b siRNA was used to down-regulate DNMT3b expression. DNMT3b and FHIT proteins were determined by Western blotting. Methylation-specific PCR was used to analyze the methylation status of the FHIT gene. RESULTS: After DNMT3b siRNA transfection, the expression of DNMT3b was inhibited in SMMC-7721 cells, and the expression of FHIT was significantly higher than that in the control group. There was no significant difference in methylation status between the DNMT3b siRNA transfected cells and control cells. CONCLUSION: DNMT3b may play an important role in regulation of FHIT expression in hepatoma SMMC-7721 cells, but not through methylation of the FHIT promoter. (Hepatobiliary Pancreat Dis Int 2009; 8: 273-277)
文摘In order to investigate the intratumoral DNA ploid heterogeneity (PH) in esophageal squamous cell carcinoma and its clinical-pathological significance, nuclear DNA ploidy of 80 cases of squamous cell carcinoma of the esophagus were determined with multiple samples removed from the same tumor, using a flow cytometry (FCM) technique. 240 samples for flow cytimetric DNA analysis were taken from 3 different parts if each tumor of 80 cases of specimens. DNA measurement was were present in a tumor or the variation in DI value among 3 peaks in each tumor was greater than 10%. Further more at last, comparison or clinical-pathological characteristics was performed between PHTs and N-PHT which has a similar ploid pattern in 3 sampling spots of each tumor (non PHT). DNA indices ranged from 0.77～1.74, and the incidence of DNA AN was 88. 8% (71/80) in this series. Of 80 cases, 38 cases (47. 5%, 38/80) showed intratumoral heterogeneity in DNA ploidy. The heterogeneity in DNA ploidy was related to the extent of wall penetration by the tumor,the incidence of lymph node metastasis and the patients's prognosis, not to histological grades and size of the tumor. There is PH phenomena in esophageal squmous cell carcinoma, and DNA PH may be a more exact indicator in reflecting the biological chatacteristics of the tumor and patient's prognosis.
文摘AIM To evaluate the relationship between the expression of Ki 67 antigen and the pathobiological behaviours of gastric cancers especially their distant metastases. METHODS Fifty six specimens of gastric cancer routinely fixed in formalin and embedded in paraffin (FFEP) were studied by immunohistochemical method. RESULTS Expression of Ki 67 antigen was significantly related to the distant metastases to liver, ovary and adrenal gland ( P <0 005), but not related to the histological type, growth pattern, depth of invasion, histological differentiation and the metastases to local lymph nodes ( P >0 05). Furthermore, the Ki 67 antigen expression was significantly related to the DNA aneuploidy pattern, which is closely related to poor prognosis ( P <0 05). CONCLUSION Overexpression of Ki 67 can be used as an objective marker of the proliferative activity for predicting prognosis of gastric cancer and metastatic potential to distant organs.
文摘Summary： To determining the postmortem interval （PMI） through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique （IAT）. The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van＇s staining, Three indices reflecting DNA in brain cells （astrocytes） and splenic lymphocytes, including integral optical density （IOD）, average optical density （AOD）, average gray （AG） were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5 36 h. A correlation between the PMI and gray parameters （IOD,AOD and AG） was identified and the corresponding regression equation was obtained. The parameters （IOD, AOD and AG） were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.
基金Supported by the National Natural Science Foundation of China,No.39570627.
文摘AIM The food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces colon and mammary gland tumors in rats and has been implicated in the etiology of human colorectal cancer. This study was conducted to examine the potentially preventive effect of Chinese cabbage (Brassica chinensis), a brassica vegetable most commonly consumed in China, against this carcinogen-induced DNA adduct formation in rats and its possible mechanisms.METHODS Sprague-Dawley rats were maintained for 10 days on basal diet or diet containing 20% (w/ w) freeze-dried cabbage powder prior to administration of a single dose of PhIP (10 mg/ kg) by oral gavage. Rats were sacrificed at 20 h after PhIP treatment and PhIP-DNA adducts in the colon, heart, lung and liver were analyzed using 32P-postlabeling technique. Levels of hepatic cytochrome P450 (CYP) 1A1 and 1A2, as indicated by 7-ethoxyresorufin O-deethylase and 7-methlxyresorufin O-demethylase activity, and cytosolic glutathione S-transferases (GSTs) towards 1-chloro-2, 4-dinitrobenzene (CDNB) in the liver, lung and colon were measured.RESULTS Rats pre-treated with Chinese cabbage and given a single dose of PhIP had reduced levels of PhIP-DNA adducts in the colon, heart, lung and liver, with inhibition rates of 82.3%, 60.6%, 48.4% and 48.9%, respectively (P＜0.01). The enzyme assays revealed that Chinese cabbage induced both CYP1A1 and 1A2 activity, but the induction was preferential for CYP1A1 over 1A2 (81% vs 51%). GST activity towards CDNB in the liver and lung, but not colon, was also significantly increased by cabbage treatment.CONCLUSION The results indicate that Chinese cabbage has a preventive effect on PhIP-initiated carcinogenesis in rats and the mechanism is likely to involve the induction of detoxification enzymes.
基金supported by the Skolkovo Foundation(Under agreement NO.G102/16 06.12.2016г.)
文摘Hypermethylation of the gene regulatory regions are common for many cancer diseases. In this work we applied GLAD-PCR assay for identificating of the aberrantly methylated RCGY sites in the regulatory regions of some downregulated genes in tissue samples of lung cancer(LC). This list includes EFEMP1, EPHA5, HOXA5, HOXA9, LHX1, MYF6, NID2, OTX1, PAX9, RARB, RASSF1 A, RXRG, SIX6, SKOR1 and TERT genes. The results of DNA samples from 40 cancer and 25 normal lung tissues showed a good diagnostic potential of selected RCGY sites in regulatory regions of MYF6, SIX6, RXRG, LHX1, RASSF1 A and TERT genes with relatively high sensitivity(80.0 %) and specificity(88.0 %) of LC detection in tumor DNA.
